With just over one year to go until London 2012, we're joined this Tuesday at 1-2pm by Locog's head of sustainability to discuss the environmental impact - and benefits - of the London games.

Previously, David Stubbs was director of the European Golf Association Ecology Unit and he established the first pan-European environmental management programme for golf courses. He has also advised the British Olympic Association on environmental matters and in 2000 he worked with the environment team at the Sydney Olympics.

David Stubbs, head of sustainability at Locog. Photograph: Locog

Whatever you want to ask about the sustainability or green credentials of next year's Olympics, this is your chance.

Want to know how its organisers plan to make it the "greenest games in modern times", as it was originally billed? Interested in how much waste the event will generate, and how it plans to deal with it, or how much renewable energy will be powering the venues? Or perhaps you'd like to ask about the possibility that the UK could be fined £175m by the International Olympic Committe if London is still in breach of air quality limits by the time of the games?

Just post your questions below - please note anything not about sustainability and the Olympics will be marked off-topic.